Uranyl acetate complex

There are a Tew compounds of alkalies, nitrate, and acetate thai have low solubilities, but most of them are quite complex in composition. For example, sodium uranyl acetate, NaUQifCHjCOOh has low solubility. Silver acetate is an exception but its solubility is moderate. 

Uranyl acetate b 1-2%, pH 4.2-4.5 Protein—nucleic acid complexes Ribosomes Tubulin Sogo et al. (45) Khulbrandt and Unwin (47) MandelkowandMandelkow (46)... 

Reinhoudt and co-workers (101-105) have reported a series of Schiff base macrocyclic polyether ligand complexes prepared via barium cation-templated Schiff base condensation of the appropriate polyether dialdehyde with a diamine, in the presence of a transition metal or uranyl acetate, followed by removal of the Ba2+ template cation on subsequent addition of guanidinium sulfate (Scheme 19). The copperdl) and nickeldl) complexes (62) and (63) exhibit reversible redox couples... 

Reports of initial work indicated that uranyl phthalocyanine complexes could be obtained from the reaction of bis(dimethylformamide)uranyl acetate with lithium phthalocyanine [ 113], or the reaction of uranyl acetate with phthalocyanine [114,115j. However, in 1964, Bloor et al. [116] reported that the reaction of uranyl... 

Figure 12 TEM micrographs of Au nanoparticle synthesis mediated hy an HRE peptide integrated heat shock protein (Hsp 60) from Sulfolobus shibatae. (a) TEM of Au /(HRE)-Hsp complex prepared from addition of AuCLt , reduced hy citrate, and negatively stained hy uranyl acetate, (b) TEM of An /(HRE)-Hsp prepared from insoluble An precursor of AuClP(CH3)3 and reduced by borohydride (unstained)...

A solution of uranyl acetate (5 g.) in 50 ml. of glacial acetic acid is heated at reflux, with stirring, with amalgamated zinc. On completion of the reduction, the slurry of Zn[U(OOCCH3)6] in acetic acid is separated from the amalgamated zinc by decantation. The complex is precipitated completely by refluxing the decantate with an excess of acetic anhydride (20 ml.). The solid is filtered on a sintered-glass crucible and washed twice with ether. 

The triacetate uranyl complex (24) is structurally similar to the trinitrate uranyl complex (6) (three bidentate ligands arranged equa-torially around the uranyl O—U—O axis). It was expected that the visible, near ultraviolet spectrum of the triacetate uranyl complex would be similar to the spectrum of U02(N03)3 as are the spectra of 1102(804)3, 1102(003)3 , and other uranyl complexes which apparently have the same structure (17). The absorption spectrum of uranyl acetate extracted into tri-n-octylamine in xylene from dilute acetic acid is different from the trinitrato uranyl spectrum. This indicates that the triacetate uranyl complex is probably not the species involved. By analogy to the uranyl nitrate system 14), formation of a tetraacetate uranyl complex might be expected. The purpose of this work is to determine the nature of the anionic hexavalent actinide acetate complexes and to identify the species involved in the amine extraction and anion exchange of the hexavalent actinides from acetate systems. 

At low acetate concentration (uranyl acetate in acetic acid) little if any triacetate complex is present as seen by the absence of the four strong vibrational peaks at about 420, 432, 445, and 460 As the acetate level is increased, these strong triacetate peaks build into the... 

We noted earlier that the principle uranyl (VI) species extracted from acetic acid by TOA-xylene is different from that extracted by TOA-chloroform (JO). To explore the effect of the solvent further we have now measured the spectra of uranium (VI) extracted with solutions of TOA in different solvents. In these experiments a O.IOM uranyl acetate solution in IV acetic acid was extracted with an equal volume of O.IOM TOA in each of the several solvents, and the spectra of both phases were measured. In most cases the extracted uranium was found to be a mixture of tri- and tetraacetato complexes. Some examples of these spectra are shown in Figure 6. 

Fig. 7. Negative-stained images of monoclonal antibodies binding to apoBlOO on LDL. (A) An equimolar mixture of LDL and each of two anti-apoBlOO monoclonal antibodies, MB47 and MB 19, were adsorbed to the carbon-coated grid, stained with 1% uranyl acetate, and examined in the electron microscope. The insert shows both open (o) and closed (c) complexes. Bar = 0.1 p.m. (B) Complexes formed between LDL and monoclonal antibodies MB47 and MB24. (From Chatterton etal., 1991.)...

Similarly, many tris(R-carbamate)dioxouranium(VI) complexes (exemplified by K[U02(Et2NCS2)3] H20) have been reported. The complexes are prepared by reacting uranyl acetate with the R-carbamate salt obtained by addition of R-amine to an aqueous solution containing equimolar amounts of carbon disulfide and potassium hydroxide. ... 

At pH 6.5-S.5 the enol form of dibenzoylmethane (formula 54.1), a reagent of the P-diketone group, forms a yellow uranyl chelate complex which has been used for determination of uranium [76,77]. It dissolves in aqueous ethanol medium containing pyridine, or may be extracted with ethyl acetate, butyl acetate, or CHCI3 [78]. 

A monomeric complex is formed by uranyl acetate with 4,4 -bipyridine U02(bipy) (acetate)2. The coordination around the U02 ion (U-O bonds of 1.769(6) A, 180°) is hexagonal. Four oxygen atoms are contributed by two acetate groups (U-O bond distances 2.450(9) A mean) and two nitrogen atoms by the bipyridyl moiety [U-N distance 2.636(77) A] [74],... 

Uranyl Acetate. The complex U02(OAc)2 cleaves HIV mRNA upon photoactivation in a uniform fashion unless the nucleic acid is associated with protein (94). Recently, it has been shown that intense, specific cleavage occurs on RNA which is bound to HeLa cell nuclear protein. Rather an imprint than a footprint, this strong cleavage indicates that the structure of the RNA and its accessibility to metal complexes in solution is changed in the presence of protein. 

The combination of spermine and uranyl acetate, on the other hand, yields well-defined toroids of electron microscopic dimensions. Usually one finds only a few percent of such compacted DNA molecules within a large population of linear or circular DNA strands, but under carefully controlled conditions quantitative compaction to toroids of quite uniform size has been achieved (Fig. 8.6.21) (Bottcher, 1998). Chromium and cobalt ammonium complexes have similar effects, but compaction yields are usually low. The least poisonous system to compact DNA toroids consists of a hydrophobic tripeptide, namely a (yai derivative with a terminal naphthalene sulfonate headgroup (Vengerov et al., 1985). 

Complexes of the macrocyclic ligands I and II were obtained in nearly quantitative yields by the Schiff-base condensation of 1,2-diaminoethane with 2,6-diacetyl- or 2,6-diformylpyridine in the presence of uranyl acetate, followed by anion metathesis (De... 

For our publication in this subject [14], we focused on elucidating the structure of cellulose acetate (CA)-U02[VI), because despite the importance of using cellulose derivatives as chelating resins for removing rare metal ions in waste- and sea-water, before year of publishing of this study, there was a lack of Information regarding the structure of cellulose acetate-U02 (VI) complexes. We had prepared cellulose acetate-U02[VI] complex samples from three degrees of substitution of viscose pulp with uranyl acetate. The role of acetyl content of CA on the amount of chelated uranium was also evaluated [Table 7.6]. 

Table 7.6a Elemental analysis, uranium content and molar conductivity of cellulose acetate (CA] samples and their complexes with uranyl acetate...

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